No major US airline made money flying planes in 2024.

Airlines are famous for being terrible businesses: thin margins, fuel shocks, a long history of bankruptcies. So how do the big US carriers stay profitable? Not by flying you anywhere. Every one of them runs a frequent-flyer program, and that program is the real company.

Diagram: break-even · $7.4B miles sold to Amex · the real airline · Delta -2.5% · American -8.3% · Southwest -19.9% · Your airline is a credit-card company that happens to fly planes.

Airlines sell their miles in bulk to banks, which hand them to you as credit-card rewards. Delta alone took about $7.4 billion from American Express for SkyMiles in 2024. Strip that loyalty money out and the flying business runs at a loss: Delta's reported 10.5% operating margin becomes about -2.5%, American's -8.3%, Southwest's -19.9%. The seats are the bait that keeps the rewards program worth having.

Your airline is a credit-card company that happens to fly planes.